salut Claudio, how much time do you leave between the 2 coat of gelcoat ? you wait until it is tacky ?
Yes, today was about 1h. The glass lamination followed 1h1/2 hour later wet on wet.
Cheers
ClaudioD
good surprise this morning !
17 hours later I demolded the deck rather easy, no tool or wood levers, just fingers and little pressure !
Certainly all due to the packing tape !
Obviously some surface finish are needed as expected, but will be done on an hard gelcoat surface with wet paper abrasive.
Twill tissue 2 x 80g/m² will be a must especially around the hatch/cockpit floor corners.
ClaudioD
Today I spent my time in ceasing the millimeters of the various elements already completed like the Fin, Bulb and Rudders.
Checking the basic tuning dimensions all recorded in this drawing :
For better options, a second hole in the bulb has been drilled and lost 20g.
The picture of all elements with paint primer. The Bulb, after repair and paint , will be laminated tomorrow
ClaudioD
Claudio,
Yet again, this is proving to be a masterclass in model rc yacht construction!!
I know you’re retired and the ‘wrong’ side of seventy (!) but you’re productivity is truly phenomenal. Waiting with much interest to see the fit out & hull to deck bond sections. As an aside, do you run you’re models on NiMH cells (4.8 or 6v) or have you converted to the Lithium variants (6.6v (LiFe) or 7.4v (LiPo))?
it sure is a masterclass in VRC building !!!
You know the more I look at your data the more I think we could do with a crash diet program for the IOM as we’re also running on 4kg of displacement with a keel of 2.5kg where yours is not far off but longer and more powerful so no context in speed - it will be in a different league, no question !!!
Hi Row,
thank you for your appreciation words.
Me too, I like to arrive to the joint affair !!!
For the time being I still intend to use NiMH cells. 4 x 800ma/h from Enelop.
This pack self made is only 55g and it allow to sail for 1/1/2 to 2 hours with an Eurgle servo.
In my opinion there is no need to have a battery pack for the full day ! and with that the gain in weight is important.
Why ! simple a boat is fast if it is light compared to the sail area and all the weights gained should be put in the bulb.
At fortiori with 4kg displacement, the weight is important in all composing parts. Of course for a prototype some waiver may be considered.
Important in my projects I to try to get a bulb/boat ratio above 70%, I like Class M that may go up to 73%. This means that a sailing boat should not heel more then 30° to keep the hull form efficiency and if does it too often, then is better to change sails
Actual my margin is still 152g and it is not bad at all !!
Cheers
ClaudioD
Hi Celtic,
nothing against IOM, I appreciate that the construction margin is very wide as such to allow wood construction. I have seen magnificent wood made boats, but probably that’s all can be appreciated from my point of view.
The bulb ‘alone’/boat ratio is rather low, below 60% . Furthermore the draft is max 42cm.
This is probably the reason why the sail area is limited to 60dm².
60dm² pushing 4kg boat , while the 123 is 76dm² pushing the same 4kg boat !
With the 123 is a complete new design independent from any Rules, I can try to exploit at the best the characteristics of the AC120, IOM and Class M , although remaining inside a acceptable dimension.
You may have noticed that the mast is much shorter then the one of the Class M and the draft is increased up to 48cm. This is offering an important righting arm that coupled with the bulb/boat ratio of 71% , the boat offer a very interesting lateral stability. Assume the 76dm² of sail area, there is 3dm² more then a Class M and lower CE, in spite of shorter LWL and some 10dm² more then the IOM, all close to similar weights!
In respect to the AC120, the 123 is at least 500g lighter for the same sail area with deeper draft and larger bulb and longer waterline length.
The aiming idea is to offer a very fast “one-design” model.
Rules will be tailored to the prototype model, for which I’m already working on.
Cheers
ClaudioD
Before proceeding for the bulb lamination, I decided to check the Fin-Bulb alignment.
Maintaining the idea to have +1° bulb tilt, the upper part of the fin shall be rectified. (see pics). The leading edge of the Fin is also become close to the vertical position. Under this condition the CLR point shall be checked again !
ClaudioD
PS :
modified the vertical egde of the Fin. This vertical edge is important because shall be orthogonal (90°) with the Water Line.
The Fin box construction and integration will be facilitated.
Some one may ask : why the opposite sloped edge ? Simply because of the weight gain, while the forward and afterward steps will be limiting the pull force when the Fin is inserted into the hull.
Because now the Fin leading edge is almost vertical compared with previous drawing, the alignment check need to be repeated to search for the CLR new position.
Cd
The modifications of the Fin/Bulb assembly has introduced no changes to the CLR and mast step position, while the bulb CG has moved forward o about 5mm and this is an appreciated thing. The mast step can be positioned as was before since the vertical line to the CE is about 2.5mm forward of the Fin edge.
All in all, I’m satisfied with this modification and I can proceed with the Bulb lamination !
ClaudioD
exactly my point - I really enjoy the IOM and I feel the boats are quite responsive but with your designs it really shows how much more potential is to get from an IOM -provided a few rule changes- When the VRC died here few years back I decided with 3 others to kick start it again with IOM for a number of reasons, one being that there are fleets a bit everywhere and I like the box rules which allows for some freedom in the boat design but is quite restrictive on the sails which keep boat performance quite close - and this can be seen over the past few EU champs and World champs where the top 10 were often different designs, but often the same usual suspects though 
for the top 20 which is very difficult to break into. Anyway a fast one-design class with a boat that looks good too is interesting as it will value more the other aspects of performance : boat handling, tactic and strategy, tuning, preparation. Budget is also a big thing for people here, even more so since that bloody recession and if the price can remain attractive ie same region as a IOM that could be a definite advantage to get IOM racers to move or to also race with a 123. this should be feasible if all the boats come from same builder, the electronics should be roughly the same as for a IOM, unless you plan to have more control on the boat and for the rigs, again once the number of rigs is limited to 3 or 4 it should keep cost down and provide for a more even playing field… anyway just my view if I may
Hi Celtic Spirit,
the IOM Rules being a “closed” rule, offer very little variations to the designer except the beam width .
For the 123 I assume that the Hull is “mono type” and thus identical for all, no swing rig used.
- Rig 1 : 78dm² max
- Rig 2 : 60dm² min
- Jib surface 50% max of Main
- Genoa as for the Jib, overlap surface not included
- Draft : 48cm max from hull bottom
- Bulb : 2950g max - lead material
- Mast : 180cm max from hatch surface
- Weight 4000g min.
- Servos no limits
I think is all !
Cheers
ClaudioD
sounds good 
Hi Celtic,
not always !!!
see picture below.
I tried to laminate the full deck with the male plug as experimental work !
Was a Mission failure !!!
To difficult pretending to laminate in one single piece the deck, hatch and cockpit at once !!!
I will wait for the classic lamination with the female mold … before taking another decision …
I was expecting that the deck construction would be difficult and pretending to imitate a thermo-formation was an utopia !
I’m just revisiting the all affair, since I believe this method IS NOT THE WAY TO GO FOR A SUCCESSFUL CONSTRUCTION
Based upon, it is not excluded to remake the full deck in 3 separated parts, the deck itself from bow to stern, the separate hatch to be bonded later and the cockpit to be inserted after cutout of the deck.
For aesthetic and strength point of view, the hatch could be 5cm longer and equally recessed in order to make the cockpit shorter.
I will show the two silhouettes asking which one would be the favorite, thank you for the suggestions
Cheers
Claudio
I would appreciate the opinion of the readers, from aesthetic point of view, which of the two option is preferred. !
Thanks
ClaudioD
As Venice enthusiastic, I could not resist to show this picture that I entitled : “Ten Centuries in One Shot” .
My thanks to Gilles Martin-Raget, the photographer !
ClaudioD
Personally I prefer your initial plan with the “short” hatch -I think it is more realistic, just my view and yes it seems moulding the deck in 3 parts seems to be the way - fair play for trying though.
Dear Claudio,
Since day one of this project, the long cockpit (short hatch) didn’t please my eyes. But, funny thing, now that I see the new flavor, I prefer the original. Maybe I got accustom to it.
[EDIT] After more thought, I know why. I prefer the smaller cockpit AND… the smaller hatch, when taken separately. Since the hatch must aesthetically encircle the mast, I guess I would then go for new design, by elimination process. But this is so easy for me to say as I am not the one redoing the work or sitting with a perfectly good female mould! And maybe there is a part in me that just want to see you do a three parts deck, just for the great pleasure of seeing your work (never thought of a webcam?).
In any case, I am sure that, once on the water, this small aesthetic consideration will be trivial. Either designs, when twirling around ALL the other snail boats, will look fantastic. In the end, I truly think that you should base your decision on technical consideration or merit. Wasn’t it the soul of this project?
Best regards
There’s more room for bikini clad babes with the short hatch. Other than that I don’t see a big difference. Is there a watertightness advantage with either one? How about windage and airflow over the deck?
Don
Thank you very much my friends !
Nothing to do with technical restrictions or constraints !
Since the beginning the decorative ideas was dictated by the Maxi Yachts, just to deviate from the AC models, like Alfa Romeo and similar as the Leopard3 from Farr.
Turning around to get some ideas, the Wally yachts offer several hints and recently I discovered the Southern Wind Yard.
After the above failure to integrate the hatch, I start to dream new issues/forms and this is my last deck/hatch. The hatch is a separated built to be integrated on top of the deck.
The picture show the SW94 and my interpretation !
The racing characteristics are, of course, not affected.
With a flat/rounded deck each one can imagine what to do above it.
Thanks again to all of you !
Cheers
ClaudioD